Mercury is the closest planet to the Sun! It may be small, but it is full of extremes. Temperatures range between -300 and 800 degrees Fahrenheit! As it zooms around the Sun every 88 days, the speedy planet is hard to spot. This informative title shows some of the many mysteries scientists have uncovered about Mercury. Its colourful photos, fun facts, and special features are sure to delight any reader interested in space!